1. Field of the Invention
The present invention relates to the field of displaying techniques, and in particular to a three-dimensional (3D) display device and display control method thereof.
2. The Related Arts
Recently, the three-dimensional display techniques develop rapidly, and are widely applied to medical, advertising, military, exhibition, game, and so on. Referring to FIG. 1, FIG. 1 is a schematic view illustrating a known three-dimensional display device. As shown in FIG. 1, a three-dimensional display device comprises a liquid crystal display 10 and a pair of shutter glasses 13. Liquid crystal display mainly comprises liquid crystal display panel 11 and backlight module 12. Liquid crystal display panel 11 can display left-eye image and right-eye image alternatingly with the light supplied by backlight module 12.
Shutter glasses 13 comprise a left-eye lens 131 and a right-eye lens 132. Both left-eye lens 131 and right-eye lens 132 comprise two polarized lenses (not shown) and a liquid crystal layer (not shown) sandwiched between the two polarized lenses, respectively. Through supplying voltage to the corresponding liquid crystal layer, the opening and closing of left-eye lens 131 and right-eye lens 132 can be controlled. During the three-dimensional display process, when liquid crystal display panel 11 displays a left-eye image, left-eye lens 131 is open and right-eye lens 132 is closed. At this point, the left-eye image is transmitted to the viewer's left eye and the right eye sees a black image. When liquid crystal display panel 11 displays a right-eye image, left-eye lens 131 is closed and right-eye lens 132 is open. At this point, the right-eye image is transmitted to the viewer's right eye and the left eye sees a black image. In other words, the left eye and the right eye of the viewer alternatingly receive the left-eye image and right-eye image, which are then composited to form three-dimensional image in the viewer's brain to obtain the three-dimensional effect.
Referring to FIG. 2, FIG. 2 is a timing sequence diagram of the three-dimensional display device of FIG. 1. As shown in FIG. 2, the y-axis of the timing sequence diagram shows the vertical position of liquid crystal display panel 11, and the x-axis shows the time. Because, in the known techniques, backlight module 12 is divided into a plurality of level areas vertically, the scanning by backlight module 12 is conducted to control the opening and activation duration of each of the level area sequentially in the top-down manner. Specifically, as shown in FIG. 2, backlight module 12 include five level areas, i.e., area S1, area S2, area S3, area S4 and area S5. Liquid crystal display panel 11 displays left-eye image and right-eye image alternatingly, wherein the time of left-eye image is T1 and the time of right-eye image is T2, T1 and T2 represents the time of an image frame. When driving, the drive signals are supplied to liquid crystal display panel 11 corresponding to each level area sequentially in a top-down manner, and liquid crystal starts to respond after liquid crystal pixel receiving drive voltage to charge. Therefore, because of the pixel design and the viscosity of liquid crystal, a period L0 is required before reaching stability. With drive signal of all areas S1, S2, S3, S4 and S5, because left-eye lens 131 is activated and closed at a later time and the drive signal of area S1 has changed from the left-eye image frame to the right-eye image frame of the next signal, and because of the delayed response time L0 of liquid crystal pixel, the left-eye image frame and the right-eye image frame will exist in area S1 simultaneously, resulting in residual image in area S1. Besides, left-eye lens 131 is open at an earlier time and drive signals are supplied to area S1, S2, S3, S4, S5 at the same time, and because of the delayed response time L0 of liquid crystal pixel, areas S1, S2, S3, S4 and S5 will be affected by the previous right-eye image frame, resulting in image residual.
Accordingly, in the known three-dimensional display techniques, the image residual is caused by crosstalk between left eye and right eye to affect the three-dimensional display effect.
Thus, it is desired to have a three-dimensional display device and display control method thereof to solve the above problems.